The pressure to close, to sweep, to make history, was too great. The Kings wilted under that pressure. They’ve let Vancouver back in the series.

They’ve stumbled in a great situation – one they’d never been in – having built a 3-0 lead in the Western Conference first-round playoff series against the top-seeded Canucks.

No eighth-seeded team had ever swept a top seed in the NHL playoffs.

The Kings couldn’t do it, either.

After taking a one-goal lead in the first period, the Kings allowed two second-period goals and another early in the third period in front of a history-seeking sellout crowd of 18,409 at Staples Center.

You’d think the pressure was on Vancouver – the Presidents’ Trophy winner – to keep the series alive when playing in an elimination game. It seemed that way for one period, but the weight of the world was squarely on the Kings’ shoulders.

That’s how they played, anyway.

The Kings still lead the series 3-1 and are headed back to Vancouver for Sunday’s Game 5.

It’s no time to panic. At least that was the message from the Kings.

“I wouldn’t say it’s a dangerous situation,” Doughty said. “It’s going to be a fun situation, being able to (try to) close out the series in front of their fans.”

Dustin Brown missed a penalty shot – just the second playoff penalty shot in Kings history – with the Kings trailing 2-1. More than three minutes later later, Henrik Sedin scored a power play goal for a two-goal Canucks lead.

It was uncharacteristic of Brown, and he knew it was a glaring missed opportunity. “That was the biggest moment of the game,” Brown said.

That mess will surely haunt Brown over the next few days. This wasn’t all on Brown. The Kings’ penalty kill unit allowed two goals, and that unit had been stellar all season.

The momentum had turned. Had Brown – who scored the winning goal in the Kings 1-0 victory over the Canucks in Game 3 – scored, the score would have been tied.

He didn’t. It wasn’t.

“I was just getting my breath,” Brown said. “I was at the end of the PK (penalty kill) and trying to catch my breath and get ready to go. It was one of those plays that obviously, I’d like to do again. (Cory Schneider) made a good save.”

The Kings looked great in the first period as they peppered Schneider – making his second start since regular Canucks goalie Roberto Luongo was benched – with 13 shots and were on that end of the ice most of the period.

The Kings had 44 shots on goal in the game but only connected on one.

Efficient, the offense was not.

Anze Kopitar scored in the first period, giving the Kings a 1-0 lead. Kopitar fooled winger Mason Raymond like Chicago Bulls guard Derrick Rose would on a crossover. He scored on a wrister and raised both arms and he and Brown embraced. It was the lone Kings’ goal to celebrate.

In the second period, the Kings scored but a debatable quick whistle disallowed the goal, and the Kings wouldn’t find the net again.

“We’re not a team that scores a lot,” Kings coach Darryl Sutter said. “There was a borderline whistle on a goal and a missed penalty shot. I could be standing here talking about a different thing.”

Sutter could’ve been talking sweeps and history and days off until learning of the Kings’ next opponent in the semifinals.

Now, Vancouver has Daniel Sedin – who returned Wednesday after suffering a concussion that saw him miss 12 games – back in the lineup with twin brother Henrik – who scored the power play goal give the Canucks that two-goal cushion.

Daniel Sedin was the only hockey player trending on Twitter in Los Angeles – probably until Brown missed that penalty shot – because people were so worried about him. Dan Hamhuis and Daniel Sedin were credited with assists on Henrik Sedin’s goal.

“It’s nice to see No. 22 (Daniel) and 33 (Henrik),” Vancouver coach Alain Vigneault said. “Obviously, (Henrik) was trying hard but to see both those guys play together – they’re such great players – with Daniel not practicing a lot … Elite players, great players, just find a way to take their game to another level.”

And so do great teams.

It wasn’t nice for Kings players to see those guys feeding off each other and finding a groove on that first line. But the bigger problem was the way the Kings played in the second and third periods. The penalty-kill unit has taken a collective hit to its confidence, and the Kings couldn’t get the puck past Schneider the last two periods.

The Kings didn’t have the offense Wednesday to make for a great team to do great things. They should still win the series, but they felt the pressure of playoff past and couldn’t close this out.

“We don’t’ want to come back here (next Tuesday) and be 3-2 in the series,” Doughty said. “Obviously, we wanted to close it out (Wednesday), but we didn’t do that.”

The Kings could have had their first playoff series sweep in history. Instead, they’ve got three days to figure out how to beat Vancouver for the third time this series in Canada.